Piston ring



Nov. 5, 1946. w. s. LOEB PISTON RING Filed Dec. 16, 1944 3 Sheets-Sheetl mmvroxz 'azzz 5. L08

W. S. LOEB Nov. 5, 146.

PISTON RING Filed Dec. 16, 1944 fisheets-sheet 2 Nov. 5, "I' -36. w, s,LQE'B I v ZAIOASZ PISTON RING Filed Dec. 16, 1944 :5 Sheets-Sheet s ringfor internal combustion-engines.

phia, Pa.

We Manufacturing Company, lPhiladeh Application December 1c, islc seriaime. scenes The present invention relates to piston rings and it relatesmore particularly to piston-rings adapted for use in internalcombustion-engines.

An object of the present invention is to provide a simple, inexpensiveand eficient piston- Another object of the present invention is toprovide a composite oil-control piston-ring made up of a plurality ofinterchangeable circumferentially-disposed and interlocked segmentsarranged in self-interlocking and form-retaining relationship.

In my Patent 2,343,915, I have disclosed a self-expanding oil-controlpiston-ring composed of a plurality of interchangeable segments formedof sheet metal or the like, suitably bent and folded to provide a baseand a pair of converging sides having free ends spaced somewhat apart;the segments being interlocked with one another (successive segmentspointing in opposite directions) and being adapted to fit within thegroove of a piston so as to provide generally triangular,radially-extending oil-passageways axially-intep mediate upper andlower, more or less continuous, cylinder-contacting ribs or lands.

, The present invention contemplates a further improved piston-ringconstruction of the general character disclosed in my aforesaid Patent2,343,915; the improved piston-ring of the present invention beingcharacterized by simplicity ofmanufacture and assembly and positivesupport against undesirable relative movement of the segments of theassembled piston-ring during use. I

For the purpose of illustrating the invention, there are shown in theaccompanying drawings forms thereof which are at present preferred,although it is to be understood that the various instrumentalities ofwhich the invention consists can be variously arranged and organized andthat the invention is not limited to the precise arrangements andorganizations of the instrumentalities as herein shown and described.

Referring to the accompanying drawings in which like referencecharacters indicate like parts throughout:

Figure i represents a perspective view of one embodiment of the presentinvention, shown in compressed installed position.

Figure 2 represents a fragmentary perspective view, on a greatlyenlarged scale, of the embodiment of Figure l.

Figure 3 represents a perspective view, on an enlarged scale, of one ofthe segments making up the embodiment of Figure l.

22 Claims. (er see-s5) Figure i represents a perspective view of asegment identical with that of Figure 3, but shown as it appears whenrotated vertically through preparatory to assembly with the segment ofFigure 3.

Figure 5 represents a vertical cross-sectional view, on an.enlargedscale, generally along the line t-t of Figural,

.Flgure 6 represents a vertical cross-sectional view generally along theline t-5 of Figure 5.

Figure 7 represents. a fragmentary perspec tive view generally similarto that of Figure 2 but showing another embodiment of the presentinvention; parts being broken away better to reveal the constructionthereof.

Figure 8 represents aperspective view of one of the segments making upthe embodiment of Figure l.

Figure 9 represents a perspective view of another segment complementaryto that of Figure 8 and used therewith in making up the embodiment ofFigure 7, shown in inverted position relative to the segment ofFigure 8.

Figure ll) represents a vertical cross-sectional view generally similarto that of Figure 5 but showing the embodiment of Figure 7.

Figure 11 represents a fragmentary perspective view generally similar tothat of Figure 2 but showing still another embodiment of. the presentinvention. a

Figure 12 represents a perspective view generally similar to that ofFigure 3 but showing one of the segments making up the embodiment ofFigure 11.

Figure 13 represents a fragmentary perspective view, on an enlargedscale, of a further embodiment of the present invention.

Figure 14 represents a perspective view of one I of the segments makingup the embodiment of Figure 13 shown in inverted position.

Figure 15 represents avertical cross-sectional view generally similar tothat of Figure 6 but showing the embodiment of Figure 13.

In one embodiment of the present invention, shown in Figures 1 to 6inclusive, I may provide a piston ring formed of a plurality 01identical interchangeable segments indicated generally by the referencecharacter is.

The segments it are constructed of sheet metal or the like formed bysuitable stamping, bending, folding, grinding and/or other manufacturingoperations in any desired sequence,

Each segment includes a base 25, a pair of converging sides 22 and apair of flanges 23 formed at the ends of the sides 22 and extendinggenerally parallel to the base 2|, The base 2|,

sides 22 and flanges 23 are preferably integrally formed of sheet metalor the like as hereinabove described.

A gap 24 is provided intermediate the free ends of the sides 22 topermit assembly of a plurality of segments in interlocked position aswill be hereinbelow described.

The distance intermediate the free outer edges forming the junctures ofthe sides 22 with the base 2|, the free edges 21 of the flanges 23 areformed along lines of radius of the cylinder in which the ring isadapted to be used so that the sides of the segments have aradially-inward taper.

However, the fold-lines 26 forming the junctures of the sides 22 withthe flanges 23 are oppositely tapered; that is, the fold-lines 26 ofeach segment diverge radially inwardly. Thus, when the segments areassembled in the manner shown in Figure 2, the fold-lines 26 ofsuccessive upper segments fit snugly against the fold-lines of theintermediate lower segment and vice versa.

The outer edges 28 of the segments 20 are given a slight transverselyconvex curvature corresponding to the curvature of the cylinder in whichthe piston ring is to be used, so that, when a plurality of the segmentsare assembled in the manner shown in Figure 1, they form a completecircleof predetermined diameter. The inner edges 23 of the segments 20may be given a corresponding transversely concave curvature as shownparticularly in Figures 1 and 2.

A central inwardly-protruding locking button 3|) is integrally formed inthe base 2| of each segment 20. Generally semi-circular notches 3| areformed in the flanges 23 adjacent the free edges 21 thereof.

The composite piston ring of Figures 1 to 6 is assembled by interlockingthe segments 20 as shown generally in Figure 2. That is, successivesegments 20 are arranged with their bases 2| alternately on top and onbottom. One side 2| of each of a pair of adjoining downwardly-openingsegments is then positioned within the generally triangular openingdefined by the free sides and base of an upwardly-opening segmentf thefree edges of the enclosed flanges fitting in abutting relationship withthe semi-circular notches 3| thereof forming a more or less completecircle fitting about 'the button 30 so as to maintain the severalsegments in radially-interlocked po- 1 sition.

, opening segment.

Due to the natural resilience of the segments 20, the free sides 22thereof can be spread apart somewhat momentarily tojincreasethetransverse dimension of the gap 24 so as to facilitate the assembly ofthe segments into a complete piston rin When the segments are assembledas described above within the groove 32 o! a piston 33 havin one or moreoil-draining openings 34 as shown in Figure 6,. the convex edges 28contact the cylinder wall 35.

The notches 3| are made slightly oversize relativeto the buttons 30 sothat a small amount of radial movement of the segments is permitted.Thus, the individual segments may adjust themselves to irregularities inthe cylinder wall 35 such as may be caused by wear.

Whenthe segments 20 are fully assembled, a generally continuous ring isformed. That is,

of the segments there is no free-end or gap as is the case withconventional one-piece piston rings.

The fully-assembled piston ring is so dimensioned as to be compressedslightly when assembled on a piston within a cylinder. Due to theresilience of the sheet metal segments 20, the assembled piston ring hasan inherent resilient tension which tends to expand it radially andcircumferentiallyso that there is no need for a separate expander springas is usually required with conventional one-piece oil-control pistonrings.

Aslcan be seen particularly in Figure 5, the abutting sides 22 andflanges 23 of adjoining similarly-disposed segments 20 formradially-extending oil passageways 36 which are generally triangular incross-section; circumferentially successive passageways 36 having theirapices disposed alternately adjacent the top and the bottom of thepiston ring. 7

As previously described, the buttons 30 and the notches 3| provideradial interlock for the segments20. The converging sides 22 form acircumferential interlock for the segments. Thus, the segments arepositively locked in position and the finally assembled piston ring willretain its shape during use and cannot come apart; it being necessary todeliberately spread one of the segments apart (by exertingcircumferentially distending forces thereon greater than would normallybe encountered during operation) in order to disassemble the ring whendesired.

During axial movement of the piston 33 within the cylinder, oil is wipedfrom the cylinder wall 35 by the cylinder-contacting edges of thesegments 20 and is sent through the passageways 36, the groove 32 andthe oil draining openings 3 34, and is returned to the crank-case (notshown) thus providing continuous lubrication for the cylinder wall 35.

The present construction permits various sizes of piston rings to beassembled from standard 'ring segments by simply employing lesser orgreater numbers of segments depending upon the diameter'of the cylinder.That is, the construction of the present invention eliminates thenecessity for maintaining stocks of many different-size piston rings tofit the cylinders of various make internal combustion engines; segmentsof a given size and given degree of curvature being capable of assemblyinto piston rings of relatively widely different diameters.

In Figures 7 to 10, I have shown another embodiment of the presentinvention. In this embodiment, segments 3|a and 3'l-b are emment and thesemi-circular notches are omitted.

. from the free edges of the flanges.

Instead, the converging sides 39 of the upper segments 31-01. areprovided with outwardlyprotruding buttons 42; corresponding indentations43 being formed on the inner edges of said sides.

The converging sides of the lower segments 3'ib are provided withinwardly-protruding buttons 4d.

As can be seen particularly in Figures 7 to 10, when the segments 3laand 3'i'b are assembled, the buttons M'of the segments 3ib fit withinthe indentations '43 on the upper segments 3la and thus provide radialinterlock between the segments. As shown particularly in Figure 10,radial oil-passageways 45 of generally triangular cross-section areprovided by the sides 35 and flanges M of successive'segments. I

The abutting edges of adjoining flanges ll provide greatercircumferential support and minimize undesirable twisting tendencies inthe IlIlg.

In Figures 11 and 12, I have shown anotherembodimentof the presentinvention. The embodiment of Figures 11 and .12 generally resembles thatof Figures 1 to 6; the piston-ring being made up of a plurality ofidentical interlocking segments $6, each having a base M, convergingsides 48 having a gap 49 therebetween, and flanges 59. Each base A? isprovided with an inwardly-protruding button 5i, one edge'of eachv of thesaid segments being transversely 'oonvexly" curved to provide acylinder-contacting surface as described in connection with theembodiment of Figures 1 to 6. The flanges 50 are provided with notches52 at their free edges. However, the edges of the flanges -50 forward ofthe notches 52 are formed at an angle as at 53; the angled edges 53 onthe two flanges 5d of each segment 36 converging radially outwardly.

As shown particularly in Figure 11, when the piston-ring is fullyassembled, the angled edges 53 of the flanges 50 form generally V-shapednotches adjacent the convexly-curved outer periphery of the ring. As a,result of this construction, the assembled piston-ring has greaterinherent radially-outward tension when installed upon a piston andwithin a cylinder and is particularly well adapted for use where highunit pressure is desired.

In the embodiment of Figures 11 and 12 I have shown the fold-linesintermediate each base it and its sides 48 formed as stralghtedges orshoulders 53; the straight edges 63 being produced by coining or othersuitable operations. These straight edges 53 (as distinguished from therounded edges shown in Figures 1 to permit the adjoining segments of thefinal assembled piston-ring to fit more closely with one another andthus to provide more nearly continuous and uninterrupted upper and lowercylinder-contacting annuli.

, It is apparent that the embodiments of Figures 1 to 6 and 7 to 10could also be formed with 3 button 56 formed thereon, converging sides51 having a gap 58 therebetween, and flanges 59 having semi-circularnotches 80 formed at the free edges thereof.

The sides 51 and flanges 59 are cut back from the radially outer convexedges 6| of the base 55.

Thus, as shown particularly in Figure 15, the assembled piston-ringcontacts the cylinder wall 35 only along upper and lower spaced ribsformed by juxtaposed upper'and lower edges 6|, thereby increasing unitpressure of the ring.

Furthermore, since the side edges 52 of the radially outermost portionof each base can be formed as a plane surface (as distinguished from therounded surfaces at the zones of juncture of the sides 571 with theradially. inner portion of the base 55) it is possible to attain acloser fit between adjoining bases in the final assembled ring. In thisway, more nearly continuous and uninterrupted surfaces are obtained inthe upper and lower cylinder-contacting ribs as is desirable, withoutthenecessity for coining operations.

By coining the fold-lines intermediate the bases and theirsides in themanner described hereinabove in connection with the embodiment ofFigures 11 and 12, it is possible to provide generally flat shouldersthroughout the entire radial dimension of the bases and thus to givestill more nearly continuous and uninterrupted surfaces for thecylinder-contacting ribs.

- The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof, and it istherefore desired that the present embodiments be considered in allrespects as illustrative and not restrictive, reference being had'to theappended claims rather than to the foregoing description to indicatethescope of the invention.

Having thus described my invention what I claim as new and desire toprotect by Letters Patent is:

1. An oil-control piston-ring comprising a plurality of individualcircumferentially-disposed bent and folded segments ofsheet metal or thelike, each of said segments being integrally formed and having a basedisposed in a generally radial plane, a, pair of converging sidesextending generally axially from said base and having a gap intermediatetheir free ends, and a pair of flanges extending generallycircumferentially outwardly from the free ends of said sides, sucmentsbeing integrally formed and having a base disposed in a generally radialplane, a'p'air or converging sides extending generally axially from thesides of said base and having a gap intermediate their free ends, and apair of flanges extending from the free ends of said sides and lying ina generally radial plane, successive segments being alternately in upperand lower positionwith the flanges of successive upper segments disposedin abutting relationship within the converging sides of the interveninglower segment and vice versa, the sides and abutting flanges ofsuccessive upper segments and successive lower segments forminggenerally triangular radially- 1 I extending oil-passageways.

3. An oil-control piston-ring comprising a plurality of individualcircumferentially-disposed bent and folded segments of sheet metal orthe like interlockingly engaged in a complete more or less continuousannulus, each of said segments being integrally formed and having abase, a locking button protruding inwardly from said base, apair ofconverging sides extending generally axially from the sides of said baseand pair or flanges extending generally circumferentially outwardly fromthe free ends oi said sides,

' said flanges having generally semi-circular notches formed at theirfree edges, successive segments being alternately in upper and lowerposition with the flanges of successive similarlypositioned segmentsdisposed in abutting relationship within the converging sides of theintervening oppositely-positioned segment, the juxtaposed notches Ofsaid abutting flanges fitting about said buttons and providing a radialinterlock between segments.

4. An oil-control piston-ring comprising a pinrality of individualcircumferentially-disposed bent and folded segments or sheet metal orthe like interlockingly engaged in a complete more or less continuousannulus, each of said segments being integrally formed and having a basedisposed in a generally radial plane, a. pair of converging sidesextending generally axially from the sides of said base and having a gapintermediate their free ends, and a pair of flanges extending from thefree ends of said sides and lying in a, generally radial plane,successive segments being alternately in upper and lower position withthe flanges of successive upper segments dishaving a gap intermediatetheir free ends, and a a ton-ring.

posed in abutting relationship within the coni verging sides of theintervening lower segment and vice versa, the sides and abutting flanges(if-successive upper segments and successive lower segments forminggenerally triangular radially-extending oil-passageways, the sides ofone set of segments having locking buttons formed thereon and'the sidesof the other set 01 segments having corresponding indentations formedthereon, said buttons and said indentations providing radial interlockbetween said upper and lower segments.

5. An oil-control piston-ring comprising a plurality of individualcircumferentially-disposed bent and folded segments of sheet metal orthe like, each of said segments beinginteg'rally formed and having abase disposed in agenerally radial 5 plane,- a pair of converging sidesextending generally axially from said base and havin'ga gap intermediatetheir free ends, and a pair of flanges extending generallycircumferentially from the mentary radial interlock intermediatesuccessive segments.

6. An oil-control piston-ring comprising aplurality of individualcircumierentially-disposed 'bent and folded segments of. sheet metal orthe i like, each of said segments being integrally formed and having abase disposed in a generally radial plane, a pair of converging sidesextending generally axially from said base and hav- 7. An oil-controlpiston-ring comprising a Plurality of individualcircumferentialiy-disposed .bent and folded segments of sheet metal orthe like, each of said segments being integrally formed and having abase disposed in a generally radial plane, a pair of converging sidesextending generally axially from said base and having a gap intermediatetheir free ends, and a pair of flanges extending generallycircumferentially from the free ends oisaid sides, successive segmentsbeing alternately in upper and lower position with the flanges ofsuccessive similarlydisposed segments arranged in abutting relationshipwithin the converging sides of the intervening oppositely-disposedsegment and vice-versa,

and complementary locking means forming part of the sides of saidsegments for providing radial interlock intermediate successive segmentsfor providing radial interlock intermediate successive segments of theassembled piston-ring.

8. An oil-control piston-ring comprising a plurality of individualcircumferentially-disposed bent and folded segments ofsheet metal or thelike, each of said segments being integrally vformed and having a basedisposed in a generally radial plane, a pair of converging sidesextending generally axially from said base and having a gap intermediatetheir free ends, and apair oi flanges extending generallycircumferentially from the free ends of said sides, successive segmentsbeing alternately in upper and lower position with the flanges ofsuccessive similarlydisposed segments arranged in abutting relationshipwithin the converging sides of the intervening oppositely-disposedsegment and vice versa, successive segments being provided alternatelywith complementary buttons and indentations for providing radialinterlock therebetween.

9. An oil-control piston-ring comprising a plurality of individualcircumferentially-disposed bent and folded segments of sheet metal orthe like arranged in the form of a more or less continuous annulus, eachof said segments being integrally formed and having a base, a pairoi'converging sides having a gap intermediate their free ends, and a pairof flanges extending from the free ends of said sides, successivesegments being alternately in upper and lower position with one sideoi'each pair of successive upper segments disposed within the convergingsides of the intervening lower segment and vice versa, radially innerportions of adjoining flanges being disposed in abutting relationshipwhile the radially outer portions of said adjoining flanges divergeoutwardly from each other.

10. An oil-control piston-ring comprising a plurality of individualcircumferentially-disposed bent and folded segments of sheet metal orthe like arranged in the form of a more or less continucus annulus, eachof said segments being integrally formed and having a base, a pair ofconverging sides having a gap intermediate their with one side of eachpair of successive upper,

segments disposed within the converging sides of the intervening lowersegment and vice versa,

said bases having axially inwardly protrudin locking buttons formedthereon, said flanges having generally semi-circular locking notchesformed at their outer edges, the edges of adjoining flanges beingdisposed in abutting relationship radially inward of said notches anddiverging radially outward of said notches.

11. An oil-control piston-ring comprising a plurality of individualcircumferentially disposed bent and folded segments of sheet metal orthe like arranged in the form of a more or less continuous annulus, eachof said segments being integrally formed and having a. base, a pair ofconverging sides having a gap intermediate their free ends, and apair offlanges extending from the free ends of said sides, successive segmentsbeing alternately in upper and lower position with one side of each pairof successive upper segments disposed within the converging sides of theintervening lower segment and vice versa, radially inner portions ofadjoining flanges being disposed in abutting relationship while theradially outer portions of said adjoining flanges diverge outwardly fromeach other, and means forming part of said segments for providing radialinterlock intermediate successive segments of the assembled piston-ring.

12. An oil-control piston-ring comprising a plurality of individualcircumferentially-disposed bent and folded segments of sheet metal orthe like, each of said segments being integrally formed and having abase disposed in a generally radial plane, a pair of converging sidesextending generally axially from said base and having a gap intermediatetheir free ends, and a pair of flanges extending generallycircumferentially outwardl rom the free ends of said sides, successivesegments being alternately in upper and lower position with the flangesof successive upper segments disposed in abutting relationship withinthe converging sides of the intervening lower segment and vice versa,said sides and said flanges being recessed from the outeredges of saidbases whereby said bases provide a pair of annular axially-spacedcylinder-contacting ribs.

13. An oil-control piston ring comprising a plurality of individualcircumferentially-disposed bent and folded segments of sheet metal orthe flanges being recessed from the outer edges of said bases wherebysaid bases provide a pair of annular axially-spaced cylinder-contactingribs, and complementary locking means forming part of said segments forproviding radial interlock intermediate successive segments of theassembled piston-ring.

14. An oll-contrcl piston ring comprising a plurality of individualcircumierentially-disposed bent and folded segments of sheet metal orthe like, each of. said segments being integrally formed and having abase disposed in a generally radial plane, a pair of converging sidesextending generally axially from said base and having a gap intermediatetheir free ends, and a pair of flanges extending generallycircumferentially outwardly from the free ends of said sides, successivesegline contact is provided at the radially outer por tions of the basesof similarly-disposed segments.

15. For use in assembling an oil-control pistonring, an integral segmentof sheet metal or the like having a base, a pair of converging sideshaving a gap intermediate their free ends, and a pair of flangesextending from the free ends of said sides generally parallel to saidbase.

16. For use in assembling an oil-control pistonring, an integral segmentof sheet metal or the like having a base, a pair of converging sideshaving a gap intermediate their free ends, and a pair of flangesextending from the free ends of said sides generally parallel to saidbase, said base having an inwardly-protruding locking button formedthereon, said flanges having semi-circular locking notches formed attheir free edges.

17. For use in assembling an oil-control pistonring, an integral segmentof sheet metal or the like having a base, a pair of converging sideshaving a gap intermediate their free ends, and a pair of flangesextending from the free ends of said sides generally parallel to saidbase, said sides having a pair of locking buttons formed thereon.

18. For use in assembling an oil-control pistonring, a pair of integralsegments formed of sheet metal or the like, each having a base, a pairof converging sides having a gap intermediate their free ends, and apair of flanges extending from the free ends of said sides generallyparallel to said base, one of said segments having a pair of lockingbuttons formed on its sides, the other of said segments having a pair oflocking indentations formed on its sides, one of said lockingindentations being complementary to one of said locking buttons whensaid segments are in assembled position.

19. For use in assembling an oil-control pistonring, an integral segmentof sheet metal or the like having a base, a pair of converging sideshaving a gap intermediate their free ends, and a pair of flangesextending from the free ends of said sides generally parallel to saidbase, one edge of said segment being transversely convexly curved andbeing adapted to form part of the cylindercontacting surface of saidpiston-ring.

20. For use in assembling an oil-control pistonring, an integral segmentof sheet metal or the like having a .base, a pair of converging sideshaving a gap intermediate their free ends, and a pair of flangesextending from the free ends of said sides generally parallel to saidbase, one edge of said segment being transversely convexly curved andbeing adapted to form part of the cylinder-contacting surface of saidpistr --ring, the

side edges of said flanges being tapered adjacent the convex. edge ofsaid segment.

21. For use in assembling an oil-control piston ring, an integralsegment of sheet metal or the like having a base, a pair of convergingsides having a gap intermediate their free ends, and a pair of flangesextending from the free ends of said sides generally parallel to saidbase, one edge of said side and said flanges being-radially recessedfrom the corresponding edge of said base.

22. For use in assembling an oil-control pistonring, an integral segmentof sheet metal or the 10 like having a base, a pair of converging sideshaving a gap intermediate their free ends, and a pair of flangesextending from the free ends of said sides generally parallel to saidbase, one edge of said side and said flanges .being radially recessedfrom the corresponding edge of said base, the sides of the protrudingportion of said base being formed as straight-line edges. v

WILLIAM S. LOEB.

